In a semiconductor device such as a volatile semiconductor memory device or a non-volatile semiconductor memory device, a plurality of types of voltage are required in order to perform the operations of writing and reading data. Therefore, in order to generate a plurality of voltages from a single internal voltage, a step-up circuit and a step-down circuit are disposed in the semiconductor device.
In recent years, there has developed a need for the speed of the operation of a semiconductor device to be improved and accordingly, for the required voltage to be generated quickly.